The present invention relates to lids that create a differential pressure within the container on which the lid is deployed and, in particular, it concerns a lid assembly with an integral pump, in which the reciprocating linear motion of the piston is actuated by rotational movement of a pump actuating element.
Several bottle cap devices are know that are configured for use in conjunction with a separate pump such that once the vacuum is created, the pump is disconnected from the cap. These devices suffer from the need to store the pump while not in used and prevent loss of the pump during such storage. Further, some of the dump mechanisms for devices of this type are expensive electrical devices that are inappropriate for consumers with a small number of containers requiring vacuum sealing.
One attempt to provide a bottle cap with an integral vacuum pump is disclosed in U.S. Pat. No. 6,637,321 to Wang. Wang's cap includes a piston style pump, the cylinder of which is deployed inside of the container on which the cap is deployed. A handle is formed on the exposed end of the piston, and the pump is operated by a push-pull motion. One drawback to this style of pump is the length of piston stroke necessary for efficient pumping. Therefore, the cylinder extends relatively far into the container, or in the case of U.S. Pat. No. 5,535,900 to Huang, the pump extends above the bottle.
Further, the bottle caps mentioned above require removal of the cap in order to access to contents of the bottle. Nor do the devices of prior art include a vacuum indication mechanism or a filter for use with powered contents in the container.
There is therefore a need for a container lid assembly with an integral pump, in which the reciprocating linear motion of the piston is actuated by rotational movement of a pump actuating element. It would be beneficial for the lid assembly to provide access to the contents of the container while maintaining the vacuum. It would be of further benefit for the lid assembly to include a differential pressure indicator. It would also be beneficial for the lid assembly to include a vacuum indicator.